DanielRicany

Hi guys I have a question. During warm to hot engine temps, in open loop if I drive the car it will run at 11.0:1-11.5:1 Air/fuel ratio. Is this safe to drive on or is it too rich?

I have another tune that corrects this problem but brings up another problem that's even worse.

Thanks for any help.

383vett

Safe but too rich. You're losing power and wasting fuel

leesvet

That's too rich for my liking.
Hot operation when lubrication needs to be at its best, running that rich washes the thin lube off the rings and cyl walls.
knowing that 14.7 is optimal, and that you DO gain a little more power with slightly richer ratios, ask yourself, is having that little bit of more power necessary to drive to work? or to the store? Because the truth is, its NOT.
IIWM,
I'd be saving the engine for times when that little bump in power would utilize it and NOT waste the engine life on everyday BS driving. A good tune should be able to get everything that engine has to offer without sacrificing the longevity of the engine. To run at more than (best guess) 12:1 is slow suicide for the motor.
JMO...

WW7

Daniel, your car should be going into closed loop around 135- 140 degrees, I saw where you said you had open loop at hot tempertures and it didn't sound right so I thought I would comment......WW

DanielRicany

I'd only be driving it like this for however long it takes to go into closed loop. Just not practical for me to wait 100 seconds before pulling away after filling up at the gas station...

DanielRicany

Guys this is not at WOT by the way. This is just normal driving in open loop.

cumbercr

On an 85, closed loop is on a timer. So it is common to start with a hot engine and drive in open loop.

cumbercr

Daniel,

Post a copy of you table for % Change to Fuel/Air Ratio vs. Coolant (Open Loop)

DanielRicany

Okay this might be a little complicated to follow, but this is how I came up with my tables.

I figured out that GM bases their tables off of 14.7:1

This is the AFR's that it comes out to.

9.59:1 -40*F - -18.4*F
10.8:1 -18.4*F - 3.2*F
11.03:1 3.2*F - 24.8*F
11.66:1 24.8*F - 46.4*F
11.89:1 46.4*F - 68*F
12.75:1 68*F - 89.6*F
13.8:1 89.6*F - 240.8*F

In the later models at 89.6*F - 240.8*F they changed the AFR from 13.8:1 to 13.25:1, so that's what I have targeted.

Judging on how mine were displayed with the values I had before the current table, I was able to figure out that mine has to be based on 22.5:1 AFR to achieve the target AFRs that GM has.

So, for example to get 13.25:1, the formula is:

22.5 - 13.25 = *9.25*
22.5 / 100 = *.225*
9.25 / .225 = 41.11% Change

So to confirm that formula, 22.5 / 100 = .225 x 41.11 = 9.25; 22.5 - 9.25 = 13.25

Now keep in mind, Tuner Pro changes whatever I type in to the closest number it has available.

So here are my CURRENT tables.

57.42
51.95
50.78
48.05
47.27
43.36
41.02
41.02
41.02
41.02
41.02
41.02
41.02
41.02

cumbercr

That table looks waaaay rich. Here's the table from my 85 tune. Forget all the math. Just try decreasing those numbers and see what happens.

21.1
12.9
11.3
7.0
5.5
-0.4
-7.8
-7.8
-7.8
-7.8
-7.8
-7.8
-7.8
-7.8

tequilaboy

41% enrichment will result in an AFR target of approx. 10.4:1. Stock settings are about 6%. What are you doing?

DanielRicany

I set the table to these values. Tuner Pro changed the -7.8 to 0.00.

Anyway, the AFR while hot with these numbers at idle was 19:1.

cumbercr

The numbers I posted are from a stock 85 tune. Enriching a little is fine, but 41% is insane.

DanielRicany

Also it burns my eyes bad at 19:1

cumbercr

Are you sure your AFR gauge is calibrated?

DanielRicany

Yes. As soon as it hits closed loop the AFR goes to 14.7:1

cumbercr

I opened the stock BIN in Tuner Pro and got these numbers. The 5.86 is basically 6% as tequilaboy pointed out. If you run that lean with these numbers then something is very wrong.

34.77
26.56
25.00
20.70
19.14
13.28
5.86
5.86
5.86
5.86
5.86
5.86
5.86
5.86

DanielRicany

That's exactly what my tuner said! And that's also exactly what my OTHER tuner said!

He must have messed something up.

I'm ready to purchase a carburetor and be done with it. Here I am over a year later still tuning...

cumbercr

Have you tried starting with a stock tune? It would likely run lean. Your injectors are basically stock, so you should be able to adjust MAF tables, tweak timing and make some PE table adjustments. If you don't have a stock BIN I'll send you one.

DanielRicany

I have a stock tune. How do I know what to set the MAF tables to? My tuner does all this. I only know the small stuff.

Thanks